Famous British hoaxes

The British band Crass was behind the "Thatchergate" hoax just
after the Falklands War 1982, when they spliced together from previous
speeches what appeared to be a shocking telephone conversation between
Margaret Thatcher and Ronald Reagan. The recording, in which Thatcher
appeared to suggest HMS Sheffield was deliberately sacrificed to drive the
war, was finally rumbled as a hoax by The Observer.